Implantable medical devices and their accompanying delivery systems are well known in the art. These implantable devices include stents, microcoils, valves and similar types of devices which are used to treat a variety of different medical conditions.
Many implantable devices are delivered within a patient by way of a catheter-style delivery device. One type of delivery system commonly used with self-expanding implantable devices utilizes two concentrically arranged catheters or shafts. The implantable device is disposed axially around a distal end of the inner catheter or pusher and held in a compressed position by the outer sleeve. Once the implantable device is positioned at a target location, the outer shaft is withdrawn, releasing the implantable device at the target location.
One drawback often associated with this type of delivery system is the inability of the user to reposition the implantable device once released. In this respect, if the implantable device deploys in an undesirable position or configuration, the user is unable to recapture or otherwise reposition the device to a desired location. Curves in the path of the catheter through the human body can cause friction and further difficulties when evenly withdrawing the outer shaft and therefore can further result in undesirable device deployment.
Other deployment systems also typically include a mechanism for selectively uncoupling the implantable device from the delivery system. For example, some delivery systems for non-expandable implants include a tether fixed to both the delivery catheter and the implantable device. When the user wishes to release the implantable device, a nearby heater melts the tether, thereby releasing the device.
In such a delivery system, a portion of the melted tether remains on the implantable device. In some procedures, this tether remnant may cause complications in the patient such as blood clots, especially if located within a blood vessel. In other procedures, this tether remnant may pose less risk for complications and therefore may be of less concern to a physician.
There remains a need in the art for an implantable device delivery system that overcomes the drawbacks of the prior art.